Conventional examples of the welding carriage suitable for fillet welding of a corner portion as described above include a welding carriage disclosed in Patent Document 1. The welding carriage relates to the invention filed by the present applicant.
More specifically, the welding carriage includes a carriage body having four running wheels disposed on the front and rear ends thereof and a torch supporting part disposed between the front and rear ends of the carriage body. The welding torch is supported in an inclined state by the torch supporting part. More specifically, the welding torch is supported so as to position its tip on a side surface side of the carriage body and so as to face diagonally downward. The torch supporting part includes a torch driving mechanism which swings the tip of the welding torch in a forward and rearward direction of the carriage body, and simultaneously positions the tip close to a welding line along the forward and rearward direction thereof.
In the welding carriage, for example, in a case of performing fillet welding on inside corners, at a stage when a wall blocks the carriage body from moving forward, the torch driving mechanism of the torch supporting part swings the tip of the welding torch in front of the carriage body, whereby the welding carriage can weld up to the corner portions without so-called unwelded portions.
During this period, the torch driving mechanism of the torch supporting part moves the welding torch toward the welding line, and thus the tip of the welding torch swung forward is positioned close to the welding line, resulting in surely providing a gas shield, and thus maintaining weld quality.